Transgenic Core Shared Resource - Project Summary/Abstract The primary goal of the Transgenic Core is to provide Cancer Center members and other investigators at the Salk Institute access to cutting-edge technologies for creating genetically altered mouse models. These transgenic lines of mice represent critical genetic tools that enable researchers to model human diseases, to analyze and functionally manipulate specific genes, and to test potential therapeutic interventions. To achieve this goal, the Transgenic Core provides state-of-the genome editing services, as well as services required to generate and maintain transgenic mice. Specific services include: 1) the microinjection of DNA constructs into early mouse embryos, 2) CRISPR/Cas9 microinjections, 3) lentiviral microinjections, 4) microinjection of gene- targeted mouse embryonic stem (ES) cells into blastocysts, 5) in-vitro fertilization (IVF), 6) embryo and sperm cryopreservation, 7) re-derivation of mouse lines provided to the Institute from non-standard sources, 8) gene- targeting in mouse ES cells, 9) targeting vector design and construction, 10) de novo derivation of ES cell lines, 11) ES cell expansion and preparation for microinjection, and 12) the generation and maintenance of DR4 and CF1 mouse embryonic feeder cells. In addition, the Core offers services for the injection of human embryonic stem cell lines and induced pluripotent stem (iPS) cell lines into immunodeficient mice to assess their ability to form teratomas. Recently the Transgenic Core has expanded services to offer: Southern blot services for confirmation of gene targeting in modified ES cells, PCR-based genotyping of transgenic mice, and mycoplasma testing. Thus, the Transgenic Core seeks to facilitate research of Cancer Center members by generating genetically modified mouse models of cancer, cryopreserving mouse lines that are not currently in use, re-deriving mouse lines provided by non-standard sources, generatimg homologous recombination-based gene targeted mouse ES cell lines, providing free consultations to match current transgenic technologies to investigator needs, and providing free training in all procedures involved in producing transgenic animals.